That modern arbiter of information, Wikipedia defines biofilm thusly:
A biofilm is any group of microorganisms in which cells stick to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS).
Biofilm is implicated in chronic disease like respiratory infections. (Randall D. Wolcott, MD; Garth D. Ehrlich, PhD, JAMA. 2008;299(22):2682-2684. doi:10.1001/jama.299.22.2682.)
Biofilm contains many different types of bacteria, yeasts, protozoans, and even fungi. Biofilm is resistant to antibiotics. Dental plaque is a type of biofilm.
Prevention and wellness-oriented dental healthcare is taking notice of research in the area of biofilm. Biofilm control is one reason why when you see our hygienists for care, it is not "just a cleaning"!
We try to use several modalities of treatment to deal with biofilm in the mouth. Mechanical alteration of the biofilm: The hygienist is disrupting and mechanically altering the biofilm with her ultrasonic instruments so that it is not as damaging to our body. Chemical alteration: The hygienist and myself may recommend the use of xylitol to change the oral environment. Xylitol cannot be metabolized by the bacteria that cause caries, so these bacteria cannot digest it and produce tooth surface damaging acid.
Fluoride is another tool that can harden the tooth surface and make it resistant to demineralization. Another way to fight destructive bacteria is competitive inhibition by introducing bacteria that do not contribute to dental decay or gum disease. Oral probiotics show promise. Your vet may already do this for your cat or dog!
So, be prepared when your hygienist mentions biofilm at your next visit and ask her to remove any extracellular polymeric substance she finds below your gumline!